Vibratory compaction/driving apparatus

ABSTRACT

A soil compactor/driver that includes a housing and a substantially sealed chamber defined within the housing. A weight assembly that is carried by the housing and includes an eccentrically mounted weight. The weight is supported for rotation within the chamber by a pair of sealed, spherical bearings that do not require maintenance. First and second end plates are adapted to receive at least a portion of an associated sealed bearing and the housing defines first and second openings associated with the first and second end plates. The end plates, bearings and weight are arranged to be preassembled outside of the housing to form the weight assembly which is then installable as a unit into the housing which substantially reduces manufacturing and maintenance costs.

RELATED APPLICATION

This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/148,146, filed on Jan. 29, 2009, the disclosure of which is entirely incorporated herein by reference.

TECHNICAL FIELD

The present invention relates generally to soil compactors/drivers and, in particular, to a soil compactor/driver with reduced manufacturing and maintenance costs.

BACKGROUND ART

Power operated soil compactors are used in the construction industry to increase the density of soil during excavation projects. In some known compactors, a unit for inducing vibrations in a base plate includes a eccentrically mounted, rotatable weight. The weight is suitably rotated, i.e., by a hydraulic motor to produce vibrations or oscillations in the compactor. It is also known to operate soil compactors using the boom of a backhoe in order to position the compactor appropriately. If a hydraulic motor is used to drive the eccentric weight, it is also known to use the hydraulic system of the backhoe to provide hydraulic fluid to the hydraulic motor in the compactor.

In at least some compactors, the weight mechanism is supported for rotation between a pair of bearings. Due to the extreme conditions under which soil compactors are operated, maintenance of these support bearings is often needed. In order to improve reliability of past soil compactors, lubricating systems have been devised to lubricate the bearings. In at least one prior art compactor, a means for delivering grease to the bearings was provided, which included passages connected with the bearing through which grease was delivered from an outside source of grease such as a grease gun. An example of a soil compactor, provided with a means for greasing the support bearings, is disclosed in U.S. Pat. No. 3,561,336.

In another type of soil compactor, lubrication was provided to the bearings using an oil sump. The rotating weight would pass through the oil in the oil sump resulting in the bearings being splash lubricated by oil. Use of an oil sump necessitates monitoring of the oil level in the compactor and it also increases the cost of the unit since the weight chamber must be sealed to prevent leakage of the oil. In both prior art designs described above, periodic maintenance was necessary. If lubrication wasn't maintained, the bearings would quickly fail, requiring a repair and costly downtime for the compactor.

DISCLOSURE OF INVENTION

The present invention provides a new and improved soil compactor/driver in which both manufacturing costs and maintenance costs are reduced. According to a preferred embodiment, the compactor/driver includes a housing in which a weight chamber is defined. Preferably, the apparatus includes mounting structure by which the housing is attached to a manipulating machine such as a backhoe. A weight assembly is carried by the housing and includes an eccentrically mounted weight which is locatable within the chamber. Rotation of the weight produces vibration/impulses in the housing. When the apparatus is used as a soil compactor, the housing is attached to a compaction plate which transmits these vibratory forces to soil and effects its compaction. When used as a driver, the housing transmits the impulses to a base plate which, in turn, is used to drive in pins, posts, etc.

According to one feature of the invention, the weight assembly is supported for rotation within the chamber by a pair of sealed bearings that do not require maintenance. In a more preferred embodiment, the sealed bearings are spherical bearings.

According to another feature of the invention, the weight assembly may comprise first and second end plates, each of the end plates adapted to receive at least a portion of one of the sealed bearings. The housing defines first and second openings associated with the first and second end plates. According to this feature, the end plates, bearings and weight are arranged to be preassembled outside of the housing. After the components are assembled, the entire assembly is installable as a unit into the housing which substantially reduces manufacturing costs and assembly time while also decreasing maintenance costs.

According to the illustrated embodiment, the housing comprises a weldment that includes two spaced-apart vertical side plates welded to a base plate and further includes a pair of abutting, inverted L-shaped plate members that are welded to the side plates. Horizontal portions of the L-shaped plates abut each other and are preferably welded together to thereby define at least a portion of the weight chamber.

Additional features of the invention will become apparent and a fuller understanding obtained by reading the following detailed description made with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a an exploded view of a soil compactor/driver constructed in accordance with a preferred embodiment of the invention;

FIG. 2 is an exploded view of a vibratory mechanism forming part of the device shown in FIG. 1;

FIG. 3 illustrates one embodiment of a weight subassembly that forms part of the vibratory unit shown in FIG. 2; and

FIG. 4 illustrates another embodiment of a weight subassembly that forms part of the vibratory unit shown in FIG. 2.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is an exploded view of an compactor/driver assembly constructed in accordance with a preferred embodiment of the invention. The assembly includes a vibratory unit indicated generally by the reference character 10 and a mounting frame 12 by which the vibratory unit 10 is attached to an operating arm such as the boom of a backhoe (not shown). As seen in FIG. 1, the mounting frame 12 includes a pair of spaced apart inverted U-shaped side plates 14 disposed on either side of a mounting plate 16. The mounting plate 16 is suitably attached to an operating/lifting arm using appropriate hardware. For example, the mounting frame may be mounted to the boom of a backhoe using the mounting arrangement disclosed in U.S. Pat. No. 5,927,665, which is owned by the present assignee, and which is hereby incorporated by reference.

The inverted U-shaped side plates 14 define four mounting legs 20 to which the vibratory/oscillatory unit 10 is attached. In the illustrated embodiment, the vibratory unit is coupled to the legs 20 by four isolation mounts 24. Details of the isolation mounts, etc., can be found in U.S. Pat. No. 3,909,149. Each isolation mount 24 is bolted to an associated leg and, in turn, is bolted to the vibratory unit 10.

As seen best in FIG. 1 and FIG. 2, the vibratory unit 10 (FIG. 1) includes a rotatable, eccentrically mounted weight 28 (FIG. 2) which, when rotated, produces vibrations/pulses in the vibration unit 10. The vibration unit 10 includes a compaction plate 30 and a vibration inducing drive unit 34 (FIG. 2) rigidly attached to the compaction plate 30.

The vibration inducing drive unit 34 includes a housing indicated generally by the reference character 40 and a rotatable weight assembly 68 that is mounted in the housing 40 and which is rotated by a drive motor 60 shown in FIG. 1. The housing 40, which is preferably a weldment, includes first and second spaced apart vertical side plates 42, 44. The side plates 42, 44, in the illustrated embodiment, have their bottom edges welded to the top of a base plate 45. A pair of inverted L-shaped plates 47, each having a horizontal segment 47 a and a vertical segment 47 b (only one is shown), define a substantially sealed chamber 43 in which the weight assembly 68 is located. In particular, the side edges of the vertical segment 47 b of each plate 47 is welded to the inside of the side plates 42, 44. A bottom edge (as viewed in FIG. 2) of each L-shaped plate 47 is welded to the base plate. The horizontal segments 47 a of the L-shaped plates 47 abut each other and are welded along the boundary indicated by the reference character 47 c. Mounting plates 48 are welded to the side plates 42, 44 and serve as mounting points for some applications.

In the illustrated embodiment, the drive motor 60 is a hydraulic motor and includes hydraulic hoses 62 for receiving and discharging hydraulic fluid. The hoses 62 extend between the hydraulic motor 60 and a control valve 64. If the compactor/driver is attached to a backhoe, the control valve 64 is suitably connected to the hydraulic system forming part of the backhoe.

As seen best in FIG. 1, each isolation mount 24 includes a mounting plate 24 a that is secured to the side plates 42, 44 of the vibratory unit housing 40. Each mount includes a second mounting plate 24 b which is secured to an associated leg 20 of the mounting frame 12. FIG. 1 illustrates bolt holes 20 a for receiving bolts from the isolation mounts.

As indicated above, the eccentrically mounted weight 28, when rotated by the hydraulic motor 60, induces vibration/impulses which are coupled to the base plate 45. If the device is used as a compactor, the boom would position the compactor on the earth to be compacted. Rotating the concentrically mounted weight 60 produces vibrations which, when transmitted to the soil produces compaction in the soil. A fuller understanding of this type of soil compactor can be found in U.S. Pat. No. 3,561,336, which is hereby incorporated by reference.

According to the invention, the vibration mechanism 68, as seen in FIG. 2, includes a support shaft 70 defining an axis of rotation for the weight 28. The weight 28 is supported for rotation between first and second bearing housings 74, 76 by a pair of associated bearings 78. According to the invention, the bearings are preferably sealed spherical roller bearings which require no maintenance. However, other types of sealed bearings are also contemplated by the present invention. As seen in FIG. 3, the first and second bearing housings 74, 76 are secured to the first and second side plates 42, 44.

According to the preferred embodiment of the invention, the vibration mechanism 68, including the eccentrically mounted weight 28, is preassembled as a subassembly and is then installed into the housing 40. As seen best in FIG. 3, the weight mechanism subassembly includes the weight 28, the first and second bearing housings 74, 76, the sealed support bearings 78 and the shaft 70 that is received and supported by the sealed bearings 78.

In the embodiment illustrated in FIG. 3, the first side plate 42 includes a relatively large opening for receiving a reduced diameter portion (or pilot diameter) 74 a of the first bearing housing 74. The second side plate 44 includes an inside circular recess 44 a for receiving a pilot diameter 76 a of the second bearing housing 76. Suitable fasteners, such as bolts, secure the second bearing housing 76 to the second side plate 44.

The shaft 70 that is rotatably supported by the sealed bearings 78 includes a splined inner bore 70 a which is adapted to receive a complementally shaped splined drive shaft (not shown) forming a part of the hydraulic drive motor 60. The splined connection allows the hydraulic drive motor 60 to be easily coupled and de-coupled from the eccentric weight mechanism 68, for maintenance and other purposes.

With the disclosed construction, the manufacture and maintenance of this unit is greatly enhanced. The eccentric weight mechanism 68, including the first and second bearing housings 74, 76 and sealed bearings 78 is pre-assembled as a unit and the entire unit is then installed into the weight housing 40. Bolts 75 are then used to secure the first bearing housing 74 to the first side plate 42 and the second bearing housing 76 to the second side plate 44. If maintenance is needed, the bolts 75 are simply removed and the entire weight mechanism 68 is removed as a unit. The use of sealed bearings eliminates the need for periodic maintenance to grease the bearings or to provide an oil sump in the weight housing 40 for lubricating the bearings. Spherical bearings suitable for this application are available from SKF and are sold under the “Explorer” designation. With the disclosed construction, both manufacturing costs and maintenance costs are reduced while increasing reliability.

FIG. 4 illustrates an alternate construction for the weight mechanism. In this construction, a weight 28′ is comprised of three separate weight elements 84 that are pressed on or otherwise suitably attached to a support shaft. Sealed bearings 78 of the type disclosed in FIG. 3 rotatably support the weight 28′ between associated bearing caps 74′, 76′. A first bearing cap 74′ includes a reduced diameter portion 74 a′ which is received by the first side plate 42. Unlike the second bearing housing 44 shown in FIG. 3, the second bearing housing 44′ shown in FIG. 4 is of a stepped construction and includes a reduced diameter portion 76 a′ that is received in a bore 44 a′ formed in the second side plate 44′. Suitable fasteners, such as bolts, secure the first and second bearing housings 74′, 76′ to the associated side plates 42, 44′. In the alternate construction, the weight mechanism is also preassembled outside the housing and is installed as a subassembly into the housing. Like the first embodiment, manufacturing and maintenance costs are reduced by the illustrated construction. The use of sealed bearings, preferably spherical sealed bearings, substantially reduces maintenance and the bearings themselves can be easily replaced once the weight subassembly is removed from the vibratory housing.

The disclosed compactor/driver device can be used, not only to compact soil, but can also be used to drive wood, steel and aluminum sheeting, beams, pilings, posts and sea walls. The disclosed unit can deliver impulses at the rate of 2100 cycles per minute by suitable operation of the hydraulic motor 60.

Although the invention has been described with a certain degree of particularity, it should be understood that those skilled in the art can make various changes to it without departing from the spirit or scope of the invention as hereinafter claimed. 

1. A vibratory apparatus for generating vibratory forces, comprising: a) a housing; b) a chamber defined within said housing; c) mounting structure for attaching said housing to a manipulating machine; d) a weight assembly carried by said housing including a centrically mounted weight rotatable within said chamber; e) said weight being supported for rotation within said chamber by a pair of sealed bearings that do not require maintenance; f) said weight assembly including first and second end plates, each of said end plates adapted to receive at least a portion of one of said sealed bearings, said housing defining first and second opening associated with said first and second end plates; and g) said weight assembly including said end plates, said bearings and said weight arranged to be pre-assembled outside of said housing and said resulting subassembly being installable as a unit, into said housing.
 2. The apparatus of claim 1 wherein said first end plate and said associated first opening have diametral dimensions that are smaller than the diametral dimensions of said second end plate and an associated second opening.
 3. The apparatus of claim 1 wherein said housing comprises a weldment that includes two spaced apart vertical side plates welded to a base plate and further including a pair of abutting inverted L-shaped plate members welded to the side plates, said base plate and to each other in order to define at least a portion of said chamber.
 4. The apparatus of claim 1 wherein said sealed bearings are sealed spherical roller bearings.
 5. A vibratory apparatus for generating vibratory forces, comprising: a) a housing; b) a chamber defined within said housing; c) mounting structure for attaching said housing to a manipulating machine; d) a weight assembly carried by said housing including a centrically mounted weight rotatable within said chamber; e) said weight being supported for rotation within said chamber by a pair of sealed bearings that do not require maintenance; and f) said weight assembly including first and second end plates, each of said end plates adapted to receive at least a portion of one of said sealed bearings, said housing defining first and second opening associated with said first and second end plates.
 6. The apparatus of claim 5 wherein said bearings are sealed, spherical bearings.
 7. The apparatus of claim 6 wherein said first and second end plates, said bearing and said weight are arranged to be preassembled outside of said housing to form said weight assembly, said weight assembly being installable as a unit, into said housing.
 8. The apparatus of claim 5 wherein said chamber is substantially sealed. 